An epoxidation catalyst is understood to be a catalyst which catalyzes the manufacture of an epoxy group containing compound. One process comprises contacting a hydroperoxide and an alkene with a heterogeneous epoxidation catalyst and withdrawing a product stream comprising alkylene oxide and an alcohol.
Catalysts for the manufacture of an epoxy group containing compound are known. EP-A-345856 describes the preparation of such catalyst comprising titanium in chemical combination with a solid silica and/or inorganic silicate. The preparation comprises (a) impregnating a silicon compound with a stream of gaseous titanium tetrachloride preferably comprising an inert gas, (b) calcining the obtained reaction product of step (a), and (c) hydrolyzing the product of step (b). The stream of inert gas also has the function of a carrier for the gaseous titanium tetrachloride. For such use, the gas is to be present in a relatively large amount.
There is a continuous interest in improving the selectivity of epoxidation processes in general, and more specifically of processes for the preparation of alkylene oxides.